1. Field of the Invention
The invention relates to a cartridge for an admixing apparatus for a manually operable apparatus for spraying water into which an additive in the form of a liquid concentrate, such as a plant protective agent has been mixed. The invention is however not restricted to only admixing of plant protective agents. The output of other chemical substances in concentrated form, for example cleaning agents is also possible with the cartridge.
2. Description of the Related Art
Manually operable devices for spraying of water into which an additive in the form of a liquid concentrate such as a plant protective agent has been mixed are usually utilized with plant protection sprayers and are connected through their water connection which is preferably a pressure connection via a pressure hose with a portable pressure reservoir. Said pressure reservoir accommodates the water which is already mixed with the respective additive and can be pressurized by way of a manually operated or motor driven air pump, causing an air cushion to be formed above the liquid level in the pressure reservoir. The disadvantage of this type of arrangement consists in that the pressure reservoir, the supply hose leading to the spraying device, the manual valve and the spray tube can be contaminated with the additive which is mixed into the water and which may be toxic or at the very least harmful to the environment. An additional disadvantage of this arrangement is that always a large volume of the mixture needs to be prepared which oftentimes is not used up and must subsequently be disposed of. In addition there is an inherent danger with these known spray devices that the additive concentrate in the water is added as an over or under dose, or in other words as an incorrect dose.
In order to overcome the aforementioned problems, a manually operated device for spraying of water whereby an admixing apparatus is utilized has become known from WO 02/051555A1. Said device includes a mixing head onto which a removable cartridge can be mounted which accommodates the concentrate.
The disadvantage of the device known from WO 02/051555A1 is that the cartridge includes a cavity in the form of a cylinder whereby the concentrated additive is moved from the cartridge into the mixing head through the repositioning of a movable piston. On the one hand this is a very expensive arrangement; on the other hand there is the problem that the admixing concentration cannot be altered easily with the mixing chamber being installed permanently in the admixing apparatus.
A fundamentally simpler design compared to the one known from WO 02/051555A1 is the design of manually operable device for spraying of such a mixture as is known for example from U.S. Pat. No. 4,406,406.
In the arrangement which is known from U.S. Pat. No. 4,406,406 the spray medium is discharged through the introduction of a water pressure into a cartridge, either by repositioning of a piston or through compression of a pressure sensitive interior reservoir. A disadvantage of the arrangement known from U.S. Pat. No. 4,406,406 is that the mixing chamber is a component of the mixing head with the same disadvantages that exist and are described in WO 02/051555A1.
A system is known from U.S. Pat. No. 1,827,502 in which a container which contains a chemical is connected with a line which can carry a solvent such as water, in order to admix the chemical into the solvent.
U.S. Pat. No. 2,584,104 illustrates a tank which is connected into a line which carries the solvents, for example water. A chemical is supplied to the flowing solvent or water from the tank and is mixed into the water.
A device for the irrigation of, for example, lawns has become known from U.S. Pat. No. 4,971,248 whereby a reservoir containing for example a chemical, is connected into a line. The chemical is metered through an outlet into a solvent, for example into a stream of water.
U.S. Pat. No. 2,857,202 illustrates an apparatus whereby again a waterline or solvent line is connected to a reservoir which contains chemicals, so that the water from the reservoir may be metered into the solvent when flowing through the line.
U.S. Pat. No. 3,897,004 illustrates a nozzle which is configured such that a fluid can be mixed into a carrier fluid.
What is needed in the art is a cartridge which, compared to the hitherto known cartridges, permits utilization of different concentrates that can always be metered optimally into the water depending for example on the plant additive or concentrate when added into the admixing device.